养殖场鸡粪废水厌氧发酵产氢性能

Hydrogen Production by Anaerobic Fermentation From Wastewater in Poultry Farms

在养殖场鸡粪废水中添加米糠提高废水的碳氮比,以经过不同预处理的厌氧活性污泥为接种物,控制发酵温度为36℃,初始pH为5.0,考察污泥预处理及底物质量浓度对发酵产氢的影响,并分析液相末端产物及发酵液化学需氧量(chemical oxygen demand,COD)去除率.研究结果表明,污泥的最佳预处理方法为热处理(100℃下加热15 min),发酵累积生物气产量和氢气产量分别为1 781和1 082.8 mL,是未处理组的2.52和5.85倍;鸡粪废水的适宜质量浓度为10 218 mg/L,此时氢气产量为185.1 mL/g,由Gompertz模型对产气量进行非线性拟合得拟合方程,说明该模型可很好地模拟发酵产氢过程;发酵结束后液相末端产物主要转化为乙酸和丁酸等挥发性有机酸,在不同底物质量浓度下COD去除率随底物质量浓度先增加后减小,在质量浓度为10 218 mg/L时达到26.9%.

Methods of sludge pretreatment and substrate mass concentration influencing fermentation of poultry dung wastewater are investigated in this research. The anaerobic conditions are as follows： temperature is 36 ℃, pH is 5.0, and rice bran fluid is added to increase w （C）/w （N） of wastewater. Meanwhile, terminal product of liquid phase and removal rate of COD of fermentation liquor are also analyzed. Results show that the best method of sludge pretreatment is heat treatment （at 100 % for 15 minutes） ; the production of cumulative biogas and hydrogen are 1 781 mL and 1 082.8 mL, 2.52 and 5.85 times untreated group, respectively. The optimum mass concentration of poultry dung wastewater is 10 218 mg/L with hydrogen yield as 185. 1 mL/g. At the end of fermentation, the products of liquid phase are organic acids such as acetic acid and butyric acid. The removal of COD varies with substrate concentration, which reaches 26.9% at the mass concentration of 10 218 mg/L.